"An apocalypse" is how she described it. My friend was referring not to the Covid-19 pandemic, but to the state of social media and the news in the age of Covid.

A jumble of random opinions, confusing statistics, and predictive models that mislead at a time when what everyone needs is clarity.

How worried should we be? Everyone's got an expert opinion, but few of them have skin in the game.

How do we make sense of the threat when the numbers are constantly changing?

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What I advised her to do is to ignore the noise, and focus on the very few things we are absolutely sure about. Death is one of them.

Let's start though, with the thing everyone is constantly reporting: "Cases". It's what every site is publishing as a running tally, like the prices of stocks or sport scores. The reality is that "cases" can be an extremely misleading number, because such a tiny proportion of the population has been tested.

In New Zealand, we've just announced we're ramping up our testing to 5000 tests a day. Sounds impressive. But even at that rate, it would take two-and-a-half years to test everyone.

Now, I'm not suggesting that everyone in New Zealand needs testing. What I am saying is that we test just a very tiny fraction of the population, and make broad generalisations from the results. Countries that test massively more, such as South Korea, can put far more faith in their "Covid cases" count being accurate. We cannot.

A drive through Covid-19 testing centre set-up in the Waikato township of Matamata. Photo / Alan Gibson
A drive through Covid-19 testing centre set-up in the Waikato township of Matamata. Photo / Alan Gibson

Hidden infection is the iceberg, and "cases" are just the tip that we can see.

What one can count on is deaths. Deaths are easier to identify, track, and account for than cases. A death from respiratory failure - lungs filled with fluid a week after a person developed a fever and cough - is a pretty clear and fairly reliable feature of a Covid death during these pandemic times.

Deaths are among the most reliable metrics in any pandemic, and the one that is the hardest to game, manipulate, misinterpret, or miscount. I'll take a confirmed death over a case, estimate, predication, or reckoning any day.

So what do we actually know about Covid deaths? What can we hang our hat on?

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We know that countries arguably like ours - highly developed, sparsely populated, market-based, English-speaking democracies - are seeing death rates about six times higher than a regular flu season.

That is to say, Covid is overwhelming these countries with six seasons worth of viral respiratory illness and deaths all at once.

New Zealand isn't ready for this sort of thing. Many emergency departments, hospital wards, and aged residential care facilities were struggling to provide adequate and timely care even before Covid existed. Care facilities are reporting they're at the breaking point already, just with the challenges of the lockdown, let alone any significant community spread.

So we can see that Covid is not going to be like the regular seasonal flu. Yet it's not like ebola either, which carries a 50 per cent death rate compared to Covid's 0.6 per cent. Covid is it's own pandemic, not a nation-destroyer like the 1918 Spanish flu pandemic, which killed around 1 per cent of the world's population, or the Black Plague which killed around one-third of the people in Europe. But deadly enough in its own right: it has already killed more people worldwide than the bird flu, swine flu, Sars, Mers, and ebola epidemics combined.

A simple death count still doesn't tell the whole story because that number varies greatly with population. A more accurate story of risk is told by the deaths per million.

It's more accurate because it's counting something that has already happened - it's not a prediction. And more useful because it doesn't depend on whether we tested enough people or whether the test was reliable. It also lets us compare across countries regardless of size.

If you want a reasonable answer to the question "how worried should we be?" consult a 'deaths-per-million' chart, find a country similar to ours which had its first Covid case weeks before we did, and read about their experience.

If we are anything like the rest of the world, we'll see large numbers of seriously ill patients requiring oxygen and critically ill patients requiring mechanical ventilation who will greatly outstrip our resources.

Dr. Gary Payinda is an emergency medicine specialist.
Dr. Gary Payinda is an emergency medicine specialist.

There is little to suggest we would get off as lightly as places such as Singapore or Germany. New Zealand's great claim is having one of the most cost effective health systems in the world. We get better health results with less money spent than almost any other developed nation. It also means that direct comparisons to other countries' health systems is difficult.

Singapore's population is almost the same as New Zealand's, but its population is urban and 50 per cent richer per capita than New Zealand. Medically, it looks nothing like us. Organisation and structure are its strengths.

Seventeen years ago, Singapore put in place an incredibly robust public health testing and quarantine system after SARS struck. Their response to Covid has been world-beating.

Just a short flight away from Wuhan, they were one of the first to get hit, yet have had only five deaths to date.


Covid19.govt.nz: The Government's official Covid-19 advisory website

Another non-comparator is Germany, richer than NZ on a per capita basis, with about 50% more doctors and hospital beds. They spend a significantly higher percentage of their national income on health, and it shows up in things like critical care: per 100,000 people, they have around 30 ICU beds while New Zealand has five.

Assuming our Covid death rates will be like theirs just doesn't make any sense.

How large will our numbers get?

A couple close comparators are Canada, with a population seven times larger than ours and 208 deaths, and Ireland with a population the same as New Zealand's and 120 deaths so far (as of 4 April).

Australia would be a comparator too, of course, but they're too early along their own pandemic curve to be useful to us, being almost as isolated as we are from the fountainhead of this contagion - air travel streaming out of China to big airports in Seoul, Dubai, Milan, London, and New York. Our smallness and remoteness has given us the gift of time.

Because we are not Seoul or Milan, we should look to countries that are like us, but ahead of us on the curve.

Two good candidates are Canada and Ireland. They are two comparators ideally situated just a few weeks in pandemic time ahead of us. What they're facing we will likely face too. We shouldn't expect markedly better or worse outcomes than them.

If you have the time, check out Canada's Ministry of Health Covid update page, or Ireland's.

Reality trumps predictions. Will their reality prove a more accurate predictor than our statistical modelling? Time will tell, but I know where I'll be looking for a preview of what's likely to come.